KR102088796B1 - The method of manufacturing electroconductive cellulose complex using radiation technology and electroconductive cellulose complex manufactured thereby - Google Patents

Abstract

The present invention relates to a method for manufacturing an electroconductive cellulose complex using a radiation technology and an electroconductive cellulose complex manufactured thereby. More specifically, provided is a method for manufacturing an electroconductive cellulose complex which comprises: a step of immersing cellulose in a solution containing an electroconductive monomer; and a step of irradiating radiation. In addition, the present invention provides an electroconductive cellulose complex manufactured by the method for manufacturing an electroconductive cellulose complex. Further, the present invention provides an electroconductive cellulose complex comprising electroconductive polymer, prepared by polymerizing an electroconductive monomer with irradiation, and cellulose. The electroconductive cellulose complex of the present invention has high flexibility and excellent electroconductivity.

Description

The method of manufacturing electroconductive cellulose complex using radiation technology and electroconductive cellulose complex manufactured thereby}

The present invention relates to a method for producing an electroconductive cellulose composite using radiation technology and an electroconductive cellulose composite produced thereby, and more particularly, to a technique for providing a cellulose composite having high flexibility and excellent electrical conductivity.

Cellulose is the most abundant material on the earth, and mainly exists as a material that makes up the cell wall of plants. In the case of cellulose and cellulose derivatives extracted from plants such as cellulose acetate, cellulose ether, cellulose ester, methyl cellulose, hydroethyl cellulose, carboxymethyl cellulose, methylhydroxypropyl cellulose, production yield is very high as chemical purification and treatment processes are required There are disadvantages of low and complicated process. However, in the case of bacterial cellulose, it is produced in a relatively simple process by microbial culture, and also has a high yield.

Bacterial cellulose is produced in the form of nanofibers that form beta (D) glucose bonds through the metabolic process of microorganisms, and the microfibers thus produced are obtained in an irregularly entangled gel form. These bacterial celluloses have excellent biocompatibility properties because they do not contain impurities such as lignin and hemicellulose compared to cellulose purified from plants.

Recently, as interest in the storage of electrical energy such as batteries and super-pegasters and tissue engineering supports using cellulose has increased, conductive polymers such as polyaniline and polyrirol in cellulose and metal or metal oxide nanoparticles, such as carbon nanotubes and graphene Cases have been reported in which nanocomposites are prepared by introducing materials having electrochemical properties such as carbon-based materials.

For example, as in Korean Patent Registration No. 0652065, a method for manufacturing a bacterial cellulose conductive film has been developed, but in the case of such a conventional method, there is a disadvantage in that the process is complicated and it is difficult to control the electrical conductivity. Therefore, it is expected that the manufacturing process is simple, but it is easy to control the electrical conductivity, so that it can be widely applied in the related fields when an electrically conductive cellulose composite is provided that can express excellent electrical conductivity.

One aspect of the present invention is to provide a method of manufacturing a cellulose composite having excellent electrical conductivity using radiation.

Another aspect of the present invention is to provide a cellulose composite produced by the method for producing an electroconductive cellulose composite of the present invention.

Another aspect of the present invention provides an electrically conductive cellulose composite.

One aspect of the present invention is a step of immersing cellulose in a solution containing an electrically conductive monomer and an oxidizing agent; And it provides a method for producing an electrically conductive cellulose composite comprising the step of irradiating radiation.

Another aspect of the present invention provides an electrically conductive cellulose composite produced by the method for preparing the electrically conductive cellulose composite.

Another aspect of the present invention provides an electroconductive cellulose composite comprising an electroconductive polymer and cellulose in which the electroconductive monomer is polymerized by irradiation.

In the electroconductive cellulose composite provided by the method of the present invention, polyaniline is coated on the surface of cellulose by radiation, and polyaniline and cellulose can be prepared in a composite having a chemical crosslinking with uniform and high bonding strength. Furthermore, the applicability as a supercapacitor was confirmed by using the electrochemical properties of the manufactured composite, and it can be applied in various fields such as batteries, electromagnetic shielding, electrochemical actuators, sensors, and anti-corrosion.

1 is an exemplary process of a method for producing an electroconductive cellulose composite of the present invention, showing an exemplary process for producing an electroconductive bacterial cellulose composite.
FIG. 2 shows the results of analyzing the electrically conductive bacterial cellulose complexes of Examples 1, 2 and Comparative Example 1 and the bacterial celluloses of Comparative Example 2 through X-ray photoelectron spectroscopy (XPS).
Figure 3 shows the change in weight during heating of the electrically conductive bacterial cellulose composites of Examples 1, 2 and Comparative Example 1 and the bacterial cellulose of Comparative Example 2.
4 shows graphs comparing the electrical conductivity of the electrically conductive bacterial cellulose complexes of Examples 1, 2 and Comparative Example 1 with the bacterial celluloses of Comparative Example 2.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. However, embodiments of the present invention may be modified in various other forms, and the scope of the present invention is not limited to the embodiments described below.

According to the present invention, a method of manufacturing an electrically conductive composite coated with an electrically conductive polymer on a surface is provided through irradiation with natural polymer, cellulose, in order to manufacture the electrically conductive cellulose composite.

In more detail, a method of manufacturing a cellulosic composite excellent in electrical conductivity produced by using the radiation technology of the present invention includes immersing cellulose in a solution containing an electrically conductive monomer and an oxidizing agent; And irradiating radiation.

According to the present invention, the electroconductive monomer may be at least one monomer selected from the group consisting of aniline, acetylene, pyrrole, thiophene, phenylene sulfide, furan, thienylene vinylene, diethylene and derivatives thereof.

For example, the derivative of aniline may be at least one selected from the group consisting of alkylaniline having 1 to 5 carbon atoms, alkoxy aniline having 1 to 5 carbon atoms, dialkoxy aniline having 1 to 5 carbon atoms, sulfonyl aniline, and nitro aniline. have. It is more preferable that the electroconductive monomer is aniline.

The oxidizing agent may be at least one selected from the group consisting of hydrochloric acid, nitric acid, sulfuric acid, ammonium sulfate, chromium oxide, manganese peroxide, perchloric acid and hydrogen peroxide.

The oxidizing agent employs at least one of strong acids such as hydrochloric acid, nitric acid, and sulfuric acid as the main oxidizing agent, and at least one of ammonium sulfate, chromium oxide, manganese peroxide, perchloric acid, and hydrogen peroxide is used as a secondary oxidizing agent, and can be mixed and used have.

When the oxidizing agent is mixed and used in this way, for example, toxicity of ammonium sulfate and the like in the ancillary oxidizing agent may be reduced. When the above main oxidizing agent and incidental oxidizing agent are used together, their molar ratio is, for example, 6: 1 to 2: 1, preferably 5: 1 to 3: 1.

On the other hand, in the step of immersing cellulose in a solution containing an electrically conductive monomer and an oxidizing agent, the solution may be subsequently washed with distilled water or the like, followed by further treatment with a solution containing only an oxidizing agent. This additionally increases the advantage. When performing the additional treatment as described above, the oxidizing agent used in the step of immersing the cellulose may be the main oxidizing agent, the oxidizing agent in the additional processing step may be a secondary oxidizing agent.

According to the present invention, a solvent that can be used for preparing a solution containing an electrically conductive monomer and an oxidizing agent may be water, for example, purified water.

The content of the electroconductive monomer is preferably 1 to 20% by weight based on the total solution, and the total concentration of the oxidizing agent is preferably 0.05 to 10 mol / L, for example, 0.5 to 1 mol / L.

On the other hand, the electroconductive monomer is a component for imparting electroconductivity to the cellulose composite, and when the content of the electroconductive monomer is less than 1% by weight, there is a problem of insufficient electrical conductivity, and when it exceeds 20% by weight, the electrical conductivity is greatly increased There is a problem in that the efficiency for increasing the concentration is reduced.

In addition, the oxidizing agent is a component for increasing the conductivity of the conductive polymer through an oxidation reaction, and when the total concentration is less than 0.05 mol / L, the electrically conductive monomer may not be uniformly bonded to the surface of cellulose, and exceeds 10 mol / L If there is, there is a problem that efficiency due to excessive oxidation reaction and biocompatibility due to toxicity of residual oxidant are deteriorated.

The cellulose used in the present invention may be microbial cellulose, bacterial cellulose, microcrystalline cellulose, cellulose derived from marine or invertebrates, cellulose derivatives, and cellulose selected from the group consisting of combinations thereof.

The bacterial cellulose is a natural polymer that is biosynthesized by bacteria, and is produced from the cellulose synthetic enzyme present in the bacteria membrane.

For example, the bacterial cellulose is of the genus Acetobacter, genus Gluconacetobacter, genus Agrobacterium, genus Rhizobium, genus Pseudomonas, and Sarsina It may be a microbial cellulose that is a bacterial cellulose selected from the group consisting of genera.

According to the present invention, the radiation is selected from the group consisting of gamma rays, electron beams, x rays and ultraviolet rays, and it is preferable to use gamma rays.

According to the present invention, irradiation causes polymerization of the electroconductive monomer, and when the radiation dose is increased, it is possible to obtain an improved electroconductivity as the polymerization of the electroconductive monomer increases.

At this time, the radiation dose is preferably 2 to 100 kGy, more preferably 5 to 50 kGy, and more preferably 10 to 25 kGy. When the dose of radiation is less than 2kGy, there is a problem that the conductivity is not improved as desired because the electrically conductive monomer does not sufficiently form a polymer. On the other hand, when the radiation dose exceeds 100 kGy, there is a problem that cellulose is decomposed.

In addition, the irradiation may be performed at a dose per hour of 10 kGy / h to 50 kGy / h. When the radiation dose per hour is less than 10 kGy / h, the process execution time may be increased, and when it exceeds 50 kGy / h, the radiation dose per hour is high to increase the oxidation degree of aniline, thereby synthesizing polyaniline with high electrical conductivity. This can cause problems that cannot be done.

The step of irradiating the radiation of the present invention is performed in a state in which cellulose is immersed in a solution containing a conductive monomer and an oxidizing agent. In case of irradiation after radiation after immersion, polymerization of the electroconductive monomer does not proceed smoothly. The results of the electroconductive intermediate body coating cannot be obtained.

According to another aspect of the present invention, there is provided an electroconductive cellulose composite produced by the method for producing an electroconductive cellulose composite of the present invention.

The electroconductive cellulose composite obtained by the present invention is a cellulose surface coated with an electroconductive polymer, and as can be seen in FIG. 2, it can be confirmed that the electroconductive monomer is included in the composite.

In particular, as can be seen in Figure 4, the method of manufacturing the electrically conductive cellulose composite according to the present invention can significantly increase the electrical conductivity according to the control of the radiation dose.

Meanwhile, according to the present invention, there is provided an electroconductive cellulose composite comprising an electroconductive polymer and cellulose in which the electroconductive monomer is polymerized by irradiation.

In the electroconductive cellulose composite, cellulose is coated with an electroconductive polymer, wherein the electroconductive polymer is polyaniline, polyacetylene, polypyrrole, polythiophene, polyphenylene sulfide, polyfuran, polythiene vinylene, polydiethylene And it is at least one selected from the group consisting of these copolymers.

The cellulose composite prepared according to the present invention has high flexibility and excellent electrical conductivity, and it is possible to easily adjust conductivity according to radiation dose.

Hereinafter, the present invention will be described in more detail through specific examples. The following examples are only examples to aid the understanding of the present invention, and the scope of the present invention is not limited thereto.

Example

1. Preparation of bacterial cellulose complex

Example 1

Hydrochloric acid 0.5 mol / L and ammonium sulfate ((NH ₄ ) ₂ S ₂ O ₈ ) A solution containing an electroconductive monomer by dissolving aniline, an electroconductive monomer, at 10% by weight in 200 ml of a mixed solution of 0.25 mol / L (hereinafter, 'A solution') was prepared. Then, 200 μm thick film-type bacterial cellulose (Zadam, Korea) was immersed in A solution and stirred at room temperature for 180 minutes.

Gamma radiation ( ⁶⁰ Co source, Pencil type, MDS Nordion, Cananda) was irradiated with a total amount of 25 kGy at an hourly dose of 10 kGy / h to the solution A in which the bacterial cellulose was immersed, and polyaniline-modified electricity was modified in the bacterial cellulose. Conductive bacterial cellulose complexes were prepared.

The method of manufacturing the electrically conductive bacterial cellulose complex as described above is schematically illustrated in FIG. 1.

Example 2

In Example 1, a bacterial cellulose complex was prepared by the same process as in Example 1, except that radiation was irradiated with a total dose of 10 kGy during irradiation.

Comparative Example 1

The bacterial cellulose complex was prepared by the same process as in Example 1, except that the bacterial cellulose was immersed in the solution for 180 minutes without irradiation in Example 1.

Comparative Example 2

Untreated bacterial cellulose in the form of a film having a thickness of about 200 νm was used as Comparative Example 2.

2. XPS analysis of the prepared bacterial cellulose complex

Bacterial cellulose complexes prepared according to Examples 1, 2, and Comparative Example 1 were analyzed by X-ray photoelectron spectroscopy, and constituent elements of the bacterial cellulose surfaces of Comparative Example 2 were analyzed. The analytical method was measured by XPS (ESCALAB-210 VG Science) machine for chemical element analysis of the polyaniline coating layer.

2 shows a graph comparing the results of the analysis. As a result, it was found that in the case of the cellulose composites of Examples 1 and 2 and Comparative Example 1, peaks showing nitrogen (N) and sulfur (S) appeared. In addition, the nitrogen peak of Comparative Example 1 is increased than Comparative Example 2, the nitrogen peak of Example 2 is increased than Comparative Example 1, and the nitrogen peak of Example 1 is increased than Example 2, so that the polymerized polyaniline is electrically conductive. It can be seen that the amount of polyaniline contained in the bacterial cellulose complex and the amount of polyaniline contained in the electrically conductive bacterial cellulose complex increases with an increase in radiation dose.

3. Measurement of the weight loss rate of the bacterial cellulose complex according to heating

The weight loss during carbonization of the bacterial cellulose composites prepared according to Examples 1, 2 and Comparative Example 1 and the bacterial cellulose of Comparative Example 2 was measured. At this time, the measurement method was that the polymerized polyaniline heated the cellulose composite using a certain amount of energy, and was performed through a TGA (Thermo Gravimetric Analysis D-TGA (SDT 2960) TA Instruments) machine. A graph comparing the results according to this is shown in FIG. 3.

As a result of heating to about 450 ° C., the bacterial cellulose complex of Example 1 remains at a weight of about 23%, and the bacterial cellulose complex of Example 2 remains at a weight of about 20%, but the bacterial cellulose complex of Comparative Example 1 is about 16% of the weight remained, and only about 15% of the bacterial cellulose of Comparative Example 2 remained. Therefore, it was found that the bacterial cellulose composite of the present invention has a remarkably low weight loss when carbonized.

4. Conductivity measurement of bacterial cellulose complex

The conductivity of the bacterial cellulose composite prepared according to Examples 1, 2 and Comparative Example 1 and the bacterial cellulose of Comparative Example 2 was measured. The conductivity was measured using a four-point probe method (Modysystems, Korea), and was measured using a linear scan voltammetry ranging from -1V to 1V. The size of the sample used for the analysis was 1 X 1 cm, and the thickness was measured using Vernier calipers (Mitutoyo, Japan). In addition, the resistance was analyzed using an I-V (Current-Voltage) curve, and the electrical conductivity was analyzed by substituting Equation (1) below using the sample thickness and resistance.

Electrical conductivity (S / cm) = 1 / (Sample thickness × resistance) ............ Equation (1)

A graph comparing the results is shown in FIG. 4.

As a result, the bacterial cellulose complexes of Examples 1 and 2 have an electrical conductivity of 0.00012 S / cm or more, but the bacterial cellulose complex of Comparative Example 1 has an electrical conductivity of about 0.000025 S / cm, and the bacterial cellulose complexes of Examples 1 and 2 are compared. It was found that it had an electrical conductivity of about 5 times that of the bacterial cellulose complex of Example 1.

In particular, as can be seen in FIG. 4, the method of manufacturing the electroconductive cellulose composite according to the present invention increases the degree of polymerization of the electroconductive monomer as the radiation dose increases, thereby significantly increasing the electrical conductivity.

Although the embodiments of the present invention have been described in detail above, the scope of rights of the present invention is not limited to this, and various modifications and variations are possible without departing from the technical spirit of the present invention as set forth in the claims. It will be apparent to those of ordinary skill in the field.

Claims (14)

Immersing cellulose in a solution containing an electrically conductive monomer and an oxidizing agent; And
Radiation irradiation
It includes,
The electroconductive monomer is at least one selected from the group consisting of aniline, alkylaniline having 1 to 5 carbon atoms, alkoxy aniline having 1 to 5 carbon atoms, dialkoxy aniline having 1 to 5 carbon atoms, sulfonyl aniline, and nitro aniline, which is electrically conductive. Cellulose composite manufacturing method. delete According to claim 1,
The oxidizing agent is at least one selected from the group consisting of hydrochloric acid, nitric acid, sulfuric acid, ammonium sulfate, chromium oxide, manganese peroxide, perchloric acid and hydrogen peroxide, a method for producing an electrically conductive cellulose composite. The method of claim 1, wherein the solution is a medium in which water is a medium. According to claim 1,
The content of the electrically conductive monomer is 1 to 20% by weight based on the weight of the total solution, the total concentration of the oxidizing agent is 0.05 to 10 mol / L, the method of manufacturing an electrically conductive cellulose composite. According to claim 1,
The cellulose is at least one cellulose selected from the group consisting of bacterial cellulose, microbial cellulose, microcrystalline cellulose, cellulose derived from marine or invertebrates, cellulose derivatives, and combinations thereof. The method of claim 6,
The bacterial cellulose is a group consisting of the genus Acetobacter, the genus Gluconacetobacter, the genus Agrobacterium, the genus Rhizobium, the genus Pseudomonas and the genus Sarsina At least one bacterial cellulose selected from the method of manufacturing an electrically conductive cellulose composite. According to claim 1,
The radiation is selected from the group consisting of gamma rays, electron beams, x-rays, and ultraviolet rays, a method for producing an electrically conductive cellulose composite. According to claim 1,
The step of irradiating the radiation is performed by irradiation with a dose of 2 to 100 kGy, the method of manufacturing an electrically conductive cellulose composite. According to claim 1,
The step of irradiating the radiation is performed by irradiation of a dose of 10 to 50 kGy / h per hour, the method of manufacturing an electrically conductive cellulose composite. delete delete delete delete

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